Men who smoked in middle age experienced more rapid cognitive decline with age than men who had never smoked, according to a recent article in Archives of General Psychiatry. Dr. Severine Sabia and colleagues examined data from the Whitehall II cohort study, a study of the social determinants of health among British civil servants, to find the association between smoking history and decline in multiple areas of cognition.
Data were obtained from 5,099 men and 2,137 women, with an average age of 56 years at the first cognitive assessment. Smoking history was analyzed over 25 years and cognition was assessed over 10 years. Four areas were analyzed: memory, vocabulary, executive function, and global function, which was created using the average scores of all tests.
Investigators reported three key findings. Men who were smokers at the time of the first cognitive test had more rapid cognitive decline than nonsmokers, and men who had only quit smoking in the past 10 years also showed greater cognitive decline. Men who stopped smoking more than 10 years ago, however, did not show more rapid cognitive decline than non-smokers.
The investigators cautioned that data from this study could not be used to determine whether men displaying a more rapid cognitive decline would ultimately progress to dementia. They also noted that their results showed no association between smoking and cognitive decline in women.
Reference: Sabia, S., et al., Impact of Smoking on Cognitive Decline in Early Old Age: The Whitehall II Cohort Study. Archives of General Psychiatry. Published online February 6, 2012.